N.J. Stat. § 54:4-100
No abatement of the principal sum of any such taxes, assessments or other municipal charges shall be made unless the governing body shall be satisfied that the market value of the property in question upon or against which such taxes, assessments or other charges have been levied, is less than such principal sum, or unless such governing body shall be satisfied that the taxes, assessments or other municipal charges are illegal in whole, or in part, or unless the proceedings taken to levy or enforce them are contrary to law. Where the taxes, assessments or other municipal charges concern personal property only, no such abatement shall be made unless the governing body shall be satisfied that the market value of the personal property which is subject to distraint to enforce payment of the said taxes, assessments or other municipal charges is less than the said principal sum.
N.J.S. § 54:4-100